The freshwater discharge from catchments along the Gulf of Alaska, termed Alaska discharge, is characterized by significant quantity and variability. Owing to subarctic climate and mountainous topography, the Alaska discharge variations may deliver possible impacts beyond the local hydrology. While short-term and local discharge observation as well as estimation has been frequently realized, a longer time span and a discussion on cascading impacts remain unexplored in this area. This study mainly focuses on estimating the Alaska discharge over several decades from 1982 to 2022, using a process-based hydrological model, namely, the Soil and Water Assessment Tool (SWAT) with modified melting processes. The adequate balance between the model complexity and the functional efficiency of SWAT suits the objective well, and discharge simulation is successfully conducted after customization in melting calculations and careful calibrations. In this seminar, I will also present the primary results related to the spatiotemporal variations in the Alaska discharge and discussion about potential relationships between these variations and atmospheric phenomena as well as the surrounding sea surface salinity, to provide a more comprehensive understanding of the atmosphere–land–ocean interactions.